1. Field of the Invention
The present invention relates to a plate making apparatus in which printing plates, on which images have been recorded by an image recording apparatus, are successively processed, punched, and subjected to plate bending.
2. Description of the Related Art
Photosensitive lithographic printing plates (hereinafter, "printing plates") used in an offset rotary press for newspapers include an OPC (organic photoconductor) photosensitive material which is formed by an organic photosemiconductor being applied to a conductive supporting body such as aluminum or the like so as to form a photoconductive photosensitive layer. There is a direct reproduction recording system which manufactures plates from this type of printing plate. In this type of a direct reproduction recording system, an image is directly recorded on the image recording surface (photosensitive surface) of the printing plate by the printing plate being charged and exposed. Generally, a printing plate of a size of two newspaper pages (approximately 1100 mm long by 400 mm wide) is used for a printing plate for printing a newspaper.
In the above-described direct reproduction recording system, the printing plate, on which an electrostatic latent image has been formed by the printing plate being charged and exposed, is subject to developing processing and fixing processing in which toner adheres and fixes to the printing plate in accordance with the image. In the developing process of the printing plate, toner is made to adhere evenly to the image recording surface of the printing plate. Thereafter, a toner image corresponding to the exposed image is formed by the toner remaining only on the image area portions of the printing plate. In the fixing process of the printing plate, the toner is heated by a fixing lamp, is filmized, and is fixed to the image recording surface. After the printing plate has been subjected to developing and fixing processing, portions of the photosensitive layer other than the image areas are eluted, and the printing plate is dried. The dried printing plate is conveyed to a punching section and a plate bending section where holes are punched in both longitudinal ends of the printing plate and both longitudinal ends are bent so that the printing plate may be loaded at the cylinder of a rotary press.
In the aforementioned system, an apparatus in which the printing plate is conveyed such that the shorter side thereof runs along the conveying direction is advantageous in terms of the processing time and the amount of space occupied. However, when the printing plate is subject to developing processing, the toner must adhere evenly to the image recording area of the printing plate. As a result, when the printing plate is conveyed along the transverse direction (widthwise direction) thereof, the toner must be applied evenly to the wide range of the length (approximately 1100 mm) of the printing plate. The devices for developing/fixing processing are therefore expensive. As a result, in the developing/fixing section, the printing plate is conveyed along the longitudinal direction thereof.
However, when the printing plate is conveyed longitudinally so that the functions of the developing/fixing section can be effectively exhibited, the devices which punch holes in both longitudinal ends of the printing plate in the punching section and which bend both longitudinal ends of the printing plate in the plate bending section interfere with the conveying path of the printing plate.